Firefox is asking me if I want to save image instead of showing it when given an image URL. How do I fix this?

When I try to get to an image URL (one that ends with .jpg, for example), FF is asking me if I want to save the image instead of loading the image in the browser.

What do I need to change to get it to just load the image so I can see it? This didn't used to happen -- I must have changed a setting and didn't realize it.

FF 32.0

Thanks!

?2014-09-03T15:09:46Z

I've never figured it out myself. It is likely something to do with how the web page itself is written, or possibly that the file isn't actually a JPEG. Sometimes it fixes itself after reloading the page or restarting Firefox.